Sleep better
Alcohol and Sleep: Why a Nightcap Backfires
Alcohol can make you fall asleep faster, but it fragments sleep later in the night, suppresses REM sleep and worsens snoring and sleep apnea. Here is what the research shows and how to drink with less impact on your sleep.
The first half and the second half
A 2013 review of the research in Alcoholism: Clinical and Experimental Research found that alcohol shortens the time it takes to fall asleep and can deepen sleep early in the night. As your body metabolises it, the pattern reverses: sleep in the second half of the night becomes lighter and more broken, with more awakenings. Many people who drink in the evening wake around 3 or 4am and struggle to get back to sleep.
Less REM sleep
Alcohol suppresses REM sleep, the stage linked to dreaming, emotional processing and memory, particularly in the first part of the night. Higher doses have larger effects. When alcohol wears off you may get a rebound of REM with vivid dreams or nightmares.
Breathing, snoring and sleep apnea
Alcohol relaxes the muscles of the throat, which makes snoring more likely and can worsen obstructive sleep apnea, increasing the number and length of breathing pauses. If you have or suspect sleep apnea, avoiding alcohol in the evening is particularly important.
Other ways it disrupts the night
- It acts as a diuretic, so you may wake to urinate.
- It can raise heart rate during sleep.
- It can trigger night sweats and reflux.
- Over time, using alcohol to get to sleep can contribute to tolerance, dependence and chronic insomnia.
Practical guidance
- Stop drinking at least 3 to 4 hours before bed, and longer after heavier drinking.
- Drink water alongside alcohol and eat with it.
- Keep amounts moderate. Effects on sleep increase with dose.
- Never mix alcohol with sleeping pills, opioids or other sedatives, which can dangerously suppress breathing.
- Try a few alcohol-free weeks and track how you feel. Many people notice deeper sleep and better mornings.
If you use alcohol to sleep
Regularly needing a drink to fall asleep is a sign the underlying sleep problem needs attention. CBT-I is the recommended treatment for chronic insomnia. If you find it hard to cut down, or experience shakes, sweats or anxiety when you stop, speak to a doctor, as stopping heavy drinking suddenly can be medically risky. In the US, the SAMHSA National Helpline (1-800-662-4357) is free and confidential.
Frequently asked questions
Does one glass of wine affect sleep?
Small amounts have smaller effects, and having it with dinner several hours before bed reduces the impact. Some people notice even one drink makes their sleep lighter, so it is worth testing for yourself.
Why do I wake up at 3am after drinking?
As alcohol is metabolised, its sedating effect wears off and sleep becomes fragmented. Dehydration, needing to urinate and REM rebound add to it.
Is alcohol bad for sleep apnea?
Yes. It relaxes throat muscles and can make apneas more frequent and longer. People with sleep apnea are generally advised to avoid alcohol close to bedtime.
Sources
This page is general information, not a diagnosis or medical advice. Read our medical disclaimer.